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Reduction and spectroscopic analysis of A-type stars in rapid rotation, with SOPHIE

» Tuesday 24 November 2020

Proposition de stage au niveau M1.

Proposant: Frédéric Royer (GEPI).

Subject: SOPHIE, at Observatoire de Haute-Provence, is an échelle spectrograph which produces high resolution data on an extended spectral range.
An observation programme was dedicated to collecting spectra for A-type stars in rapid rotation, observed at high signal-to-noise ratio. The automated SOPHIE pipeline produces reduced and sience-ready but is not completely suited to our scientific needs : fitting high SNR Balmer profiles for A-type stars. In this effective temperature range, these profiles are very deep and wide, hence one should carefully subtract the diffused light and calibrate the instrumental response to merge the échelle orders.
The aim of this internship is to implement the optimal extraction, the subtraction of the diffused light and the calibration of the instrumental response, test them and apply them to the programme data: A-type stars in rapid rotation. Eventually, the spectral synthesis of the Balmer profiles will constrain the gravity of these stars.
Spectrocopic data are in FITS format, and the code will be written in Python.